Apparatus and process for drawing glass.



R. S. PEASE.'

APPARATUS AND PROCESS. FOR DRAWING GLASS.

APPLICATION m50 MINE 5 1915.. 1,299,019, Putffltld A111'. 1,1919

2 SHEETSSHEU 2.

717/0/ mvENTon ATTORNEYS ROGER S. PEASE, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR-TO PITTSBURGH PLATEA GLASS COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION F PENNSYL- VANIA.

meente.

Application filed June 5, 1315.

To all w hom 'it may concern.'

Be it lknown that I, ROGER S. Paese, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a certain new and useful Apparatus and Process for Drawing Glass,-of which the following is a specification.

This invention relates to apparatus and process for drawing glass articles, and more particularly to thatclass of apparatus for drawing window gass; and has for its principal objects, the provision of a device whereby hollow tubes of glass may be drawn having at sides which may be cut into commercial sizes without rst having to be flattened as is the practice now generally in use wherein glass cylinders are drawn and subsequently flattened by hand in an oven to form tlat sheets; the provision of an apparatus whereby a'superior quality and tinish may be given to the finished product, and such other objects as may hereinafter appear. One embodiment of the invention, together with modifications thereof, is shown Ain the accompanying drawings, wherein-- Figure 1 is a plan view of the preferred form of apparatus; Fig. 2 is a longitudinal section of the apparatus taken onthe line IIII of Fig. 1; Fig. 3 is a longitudinal section through a modified form of the apparatus; Fig. 4 is a plan view of a portion of the apparat-us shown in Fig. 3; Fig. 5 is a longitudinal section through another modification of the device and Fig. 6 is a plan view of the forming block shown in Fig. 5. v Referring more particularly to Figs. 1 and 2 the preferred form of the apparatus consists of a glass melting tank 1 in which the molten glass 2 is melted and refined and then supplied to a forehearth 3 through the passagef. The forehearth comprises a central drawing basin 5 supplied with molten glass from an annular compartment surrounding the basin, through a plurality of spaced passages 7. y

A conical drawing ring 8 is supported within the drawing'basin and the glass used Speciicaticn of Letters Fatent.

Y AIPARATUS AND PROCESS FOR DR'WING GLASS.

Serial No. 32,364.

lin formingwthe glass cylinders or tubes is supplied through an opening in the bottom of the said ring. The forehearth is provided with a cover 9 having a central opening surrounded by an annular depending flange 10 which abuts the top edge of the drawing ring, thereby shutting olf the heat within the forehearth from the interior of the drawing ring.

A series of passages 11 eut in the lower edge of the depending flange permits heat to enter the drawing ring, the said passages being closed by means of drop gates 12. By raising and lowering these gates the temperature within the drawing ring may be regulated and uniformly maintained during the drawin operation..

The portion of the apparatus above described is more fully described in the copending application, Serial No. 32,366, the apparatus therein illustrated 'being a forehearth ,for drawing glass articles in which uniform temperature of the glass in the drawing ring may be maintained.

While the apparatus about to be described is shown in use with such a forehearth because of the uniform temperature maintained thereby, it is obvious that other forms of forehearths may be used to advantage.

Extending from the bottom of the drawing basin 5 is a pedestal 13 projecting above the surface of the glass, and upon which is mounted a metal pla-te 14- which carries four arms or forming members 15 pivoted to the plate at 16 and projecting radially from the center of the plate 14. The free ends of the arms 15 are provided with forming rollers 17 having rounded faces, and the arms may be raised to the position A'vshown in dotted lines by means of the cables 18 which are secured to the arms 15 and extend downward over pulleys 19 through a hole in the llatented Apr. l,

center of the pedestal 13. The loweii,y ends of the cables -18 are secured to a horizontal shaft 2O which isfoperated by a hand wheel 21' which may be held in adjusted positions by anyv suitable locking mechanism., By winding or unwinding `the cables 123 by turning the hand wheel 21, the arms may glass beneath the rollers 17 will be be raised or lowered.

For the purpose of drawing a cylinder or tube B, a suitable baitv22 is provided, the l may be round or square and` shape of which beginning with the arms l5 in the position A indicated Iby dotted lines the operation is as follows:

The bait is first lowered into the molten glass through the opening in the cover while vthe gates 12 are in the position shown. At

such time the raised formingarms 15 will ,enter 't-he baiit. 'After the bait has securedv a gathering of glass it is slowly, elevated, and

if desired air may be admitted through the ameter than the interior of the bait collar 2 4. After the bait has been elevated sulficient distance'for the rollers 17. on the arms 15 to clearthe bait, the arms are lowered into engagement with the walls of the cylinder. As the bait continues to i'ise the plastic stretched until the curvature of the cylinder wall disappears and the rollers becomes straight and vflat. The top -the main body ofthe molten glass.

of the cover is so positioned to maintain the proper temperature adjacent the rollers 'so that the glass will become chilled sufliciently to set immediately after it has passed theu i.` It will be noted that due to the property of cohesion, the glass beneath the rollers 1"( circumference of the circle where it leaves the glass. Therefore, in order for the glass to pass the rollers it must vbe stretched, andl in stretching, the wall lof the cylinder extending between any two rollers is flattened and remains so on account of becoming set immediately after passing the rollers.

The cylinder below the rollers is maintained in plastic condition by heat radiated `from the surface of the glasswithin the drawing ring and by heat admitted under -the gates 12 through the passages llfwhen necessary. After the polygonal tube has been formed at `the start, the air supplied through the pipe 23 may be cut olf, Aand under certain conditions maybe, dlspensed with entirely from the beginning of the operation to the end thereof. l

After the polygonal tube has it .is detached from the body been drawn of. glass by lifting the gates 12 andv allowing thehot- .gases in the forehearth to melt it off at the bottom.

to blow out a cylinder of larger di.

sheet of glass Abetween the .more or. fewer flats-ides may The tube is then taken down and 'paratus cut up into sheets inany suitable manner,

without the necessity of flattening,`whicli is an expensive operation and one which mars the surface of the glass; l. Referring to Figs. 3 and' 4, a, modified form of forming members is shown, wherein blocks ofbass wood or soap stone, or bars y of copper 25 may be used instead of pivoted arms provided with rollers. AThe bars 25 are rounded at their vends and corners vand are mounted in guid'es'26`s'ecured as to the plate 14, and` may be adjusted outwardly or toward the center of the plate and ,secured in adjusted bait '22 members is of suieient size to' fit over the positionby the set screws 27 The used with this form of forming members 25 when it is dipped in the glass,

without requiring any movement of the forming members, and a polygonal cylinder may then be drawn over the forming members in a manner similar to the operation previously described/ The cover 10', is provided with an opening 10,-similar in contour to the polygonal or square tube being drawn, such form being shown yto` illustrate variations which might be'l made in the opening in the cover to meet variousoperating conditions.

Figs. and 6 illustrate another modified form wherein the forming member 28 con; ssts of an under cut frame vof bass-wood, soap stone, or other suitable material that will not scratch or mar the glass. This bass-wood frame is carried by the cover and serves to lfia-tten the walls of the tube as it is being .i drawn, the glass being pressed against rthe inner face of the bass-wood or soap stone forms by means of air pressure constantly supplied to tlieinterior 'of' the tubeby means of the pipe 23 usual form ofl drawing bait 23".

attached to the In operation, the bait is first lowered into the glass and a cylinder is 4started in the usual manner. The bait is, slowly raised face of the bass-wood or soap stone forin-` ing frame. The pressure is maintained at this point during the entire format-ion of the tube. The finished tube is subsequently' eut ofl, taken down, and cut up in themanner 4 previously. described.

While the apparatus illustrated shows constructions for making 'tubes hav-ing four fiat sides, it is obvious that tubes having be formed by thel employment of apparatus similar to that above described, and that inanychanges inl detail' might be made without departing from the' spirit ofmy invention. i

What I claim is: l 1."1n combinationinV a glass drawing apmeans for.4 drawing a. glass tube from a body of moltenglass, and means for intacte forming'itinto a polygonal tube comprising a plurality ot" forming members engaging the walls of the tube at spaced points only and adapted to flatten the said walls as the tube drawn past the forming members.

2. In combination in a glass drawing apparatus, means for drawing' a .glass tube from a body of molten glassi'and means for `forming it into a polygonal tube comprising a plurality of spaced forming members engaging the walls of thetube at remote points only and adapted to flatten the walls thereoi eatendingbetween the forming members as tlieutube is drawn past the said forming members. s

3K ln combination in a glass drawingr apparatus', means for drawing a glass. tube fronrabodyof molten glass, and means for forming it into a polygonal tubevcomprising a plurality of spaced forming members engaging the interior surface of the walls of the tube at remote points only and adapted to flatten them as the tube is drawn past the forming members.

4. In combination in a glass drawing apparatus, means for drawing a glass tube from a body of molten. glass, and means for forming it into a polygonal tube comprising a plurality of radially disposed forming' members engaging the glass at spaced points only and adapted to flatten the walls of the tube between such points as the tube is drawn past the forming members.

ln 'combination ina glass drawing apparatus, means :for drawing a glass tube from a body of molten glass, and moans for forming it into a polygonal tube comprising a plurality of spaced forming members engaging the walls of the tube :it-remote points only and adapted to stretch the glass extending between the forming members into flat surfaces as the tube is being drawn past the forming members.

6. In combination in a glass drawing apparatus, means for drawing a glass t from a body of n'n'lten glass, and means for forming it into polygonal tube comprising a plurality o? lradially spaced forming -members having contact rollers` engaging the walls of the tube at remote points only and adapted toiletten the wallsl thereof extending between tliie forming members as the tube is drawn past the said forming members. l f

7. In combination in a glass drawing apparatus, means for drawing a glass tubit' from a body. of molten glass, and meanjsltor forming it into a polygonal tube comprising a plurality of adjustably mounted spacedforming members engaging the walls of the tube at remote points only and adaptedto Hatten them as the tule is drawn past lthe forming members. l

'8. ln combination in a glass drawing apparatus.'mea ns for drawing'a glass tube trom a body of molten glass, and means for Jforming itinto a polygonal tube comprising a plurality otl spaced pivoted forming members engaging the walls of the tube at remote points only and adapted to flatten them as the tube is drawn past the forming members.

9. In combination in a glass drawing apparatus, means for drawing a glass tube from a body ol" molten glass. and means for forming it into a polygonal tube comprising a plurality of forming members engaging the walls oi the tube at remote points only and adapted to flatten the said walls before the glass has become set, and as the tube is drawn past the forming members.

10. In combination in a glass drawing apparatus, means for drawing a glass tube from a body of molten glass, means for forming it into a polygonal tube, a plurality of spaced forming members engaging the walls ofthe tube at remote points only and adapted tov` stretch under extending between the forming members, into flat surfacesas the tube is being drawn past the forming members, and meansfor regulating the tension applied by the forming members.

l1. ln combination in a glass drawing apparatus, means for drawing a glass tube from a body of molten glass, (means for forming it into a polygonal tube comprising a. plurality of spaced forming members engaging the walls of the tube at remote points only and adapted to flatten the said walls as the tubeis drawn past the forming members, and means for varying the relative position of the flattening members with respect to the surface of the molten glass.

12. In combination in a glass drawing apparatus, means for drawing a glass tube from a. body of molten glass, means for forming it into apolygonal tube comprising a plurality of forming members engaging the walls of the tube at remote points only and adapted to flatten the said walls before the glasshas become set and as the tube is drawn past the forming members, and a shield for regulating the temperature of the glass adjacent the 'forming members.

13. The herein described process of forming window glass, which consists in drawing trema body of molten glass a glass tube and 4thcn in forming the tube into a polygonal ltube by drawing it over a plurality of stretching members engaging the Walls of the tube at separate remote points only to flatten the glass between such points before the glass in the tube sets.

14. The herein described process of forming window glass, which consists in drawingr from a body et molten glass a glass cylinder, and then in forming the cylinder into a polygonal tube bydrawing it over a plurality of stretching members engaging the walls of the cylinder at separate remote comprising a plurality of spaced forming points to -iatten the glass between such members engagmgthe walls of ,the cylinder points before the glass. in the cylinder sets. at remote points only and adapted to Hatten 10 15. In combination in a glass drawing apthe walls -thereof extending between the 5 paratus, means for drawing a glass cylinder forming members as the tube is drawn past from a body of molten glass, and means for the said forming members. forming the cylinder into a polygonal tube ROGERl S. PEASE. 

